Wax Deposition Modeling in Oil Pipelines Combined with the Wax Precipitation Kinetics

Wax deposition is one of major challenges in petroleum production and transportation. The formation of wax deposition reduces the effective pipe radius and decreases flow capacity of the pipe. Highly waxy crude oils can cause a blockage of a pipeline because of wax deposition during production and transportation of the crude oil. Wax deposition costs can be significantly reduced if wax deposition can accurately be predicted. The target of wax deposition modeling is to predict wax content and the thickness of deposition with location and time. For wax deposition modeling، it is required to study this phenomenon in laboratory flow loop experiments to investigate effective operation conditions such as flow rate on wax deposition. For wax deposition modeling، heat and mass transfer coefficients should also be calculated. Studies show that in laminar flow conditions، mass transfer coefficient can easily be calculated from Chilton-Colburn analogy. The use of analogy in turbulent flow conditions for calculating mass transfer coefficient overestimates the amount of wax deposition. In this work، a computational wax deposition model combined with the wax precipitation kinetics in the boundary layer was developed. If wax precipitation kinetics can accurately be predicted، it can significantly reduce mass transfer coefficient in turbulent flow conditions. Herein، a wax precipitation coefficient model for the prediction of mass transfer coefficient is suggested and shows that when wax precipitation coefficient increases، mass transfer coefficient decreases.